Promoted Cr-poisoning tolerance of La2NiO4+δ-coated PrBa0.5Sr0.5Co1.5Fe0.5O5+δ cathode for intermediate temperature solid oxide fuel cells

Cr-poisoning effect on pure double-perovskite PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) cathode and La2NiO4+δ (LN)-coated PBSCF cathode is investigated. During the Cr poisoning test at 750 °C in the presence of SUS430 interconnect, the electrochemical performance of pure PBSCF cathode shows severe degradation, and the significant increase in RP is mainly contributed by the increased RL. The BaCrO4 deposits are identified on the PBSCF cathode surface. LN-coated PBSCF cathode, by contrast, shows remarkable tolerance towards chromium. The reaction between volatile Cr species and PBSCF cathode can be prevented by a dense LN coating. Thus, a more stable electrochemical performance is achieved by LN-coated cathode during the Cr poisoning test. The results indicate that the introduction of LN coating not only improves the cathode electrochemical performance, but also prevents the cathode from being poisoned by chromium.